33 
the body have assumed that such thyroid is active (Neumeister, Miwa 
and Stoeltzner, Hutchinson). Those, on the other hand, who have 
studied the question from the pharmacological side, i. e., in the same 
way as other drugs are studied, have denied that such thyroid has any 
physiological activity (Eoos, Oswald, Yon Cyon and Oswald). 
One of the present writers® stated in a preliminary paper that he 
had found thyroid free of iodine to have a low degree of physiological 
activity. The experiments upon which this statement was based 
will now be described in detail. 
The thyroid most frequently used in these experiments was ob- 
tained from infants who had died of various diseases. About 80 such 
glands were dried at 50° to 60° C., powdered, and thoroughly mixed. 
There were also available small amounts of thyroid from Maltese 
kids, an Alaskan bear, and an aoudad. * * * * * 6 None of these preparations, 
when examined by the usual method for detecting iodine in the 
thyroid, gave even a qualitative test for this element. 0 
That the thyroids of children usually contain little or no iodine was 
first pointed out by Baumann. d This investigator found that the 
presence or absence of iodine and the amount of the latter, when 
present, varied according to the locality from which the glands were 
obtained. Nine of twelve thyroids of infants under 1| years of age, 
from Freiburg, contained no iodine; three contained from 0.007 to 
0.015 per cent. Of six infants from Berlin 1J years or less of age the 
thyroids of five contained from 0.014 to 0.033 per cent of iodine; 
those of the sixth contained none. The thyroids of six children from 
Hamburg had an average iodine content of 0.07 per cent. 
Miwa and Stoltzner e examined the thyroids of twelve infants from 
Berlin; in but one was iodine found, and then only to the extent of 
0.025 per cent. Weiss f examined the thyroids of seven children 
under 4J years; the iodine varied from traces to 0.037 per cent. 
that these traces of iodine are responsible for the physiological effects we attribute to 
“iodine free” thyroid. On the other hand; if these thyroids were found to contain 
traces of iodine it does not follow that this iodine was in the form of combination 
peculiar to the thyroid. 
a R. Hunt, J. Am. M. Ass., Chicago, 1907, 49, 1324. 
& We are much indebted to Dr. J. R. Mohler, Chief of the Division of Pathology, 
Bureau of Animal Industry, Department of Agriculture, and pathologist to the 
National Zoological Park, for the thyroids of these and of a number of other rare 
animals. The children’s thyroids were obtained from Baltimore. In this connection 
it may be mentioned that H. G. Wells (J. Am. M. Ass., 1897, 29, p. 1011) found the 
average percentage of iodine in the thyroid of six adults of Baltimore to be 0.236. 
c Two gms. of the children’s thyroids, 1 of the Maltese kids, 1 of the Alaskan bear, 
and 0.3 of the aoudad were used for the tests. 
d E. Baumann, Ztschr. f. physiol. Chem., Strassb., 1896, 22, p. 11. 
e S. Miwa and W. Stoltzner, Jahrb. f. Kinderh., 1897, 45, p. 87, 
/ F. Weiss, Miinphen. med. Wchnschr., 1897, 44, p. 6, 
61494— Bull. 47—09 3 
